ST72T774J9B1 STMicroelectronics, ST72T774J9B1 Datasheet - Page 19

• Manufacturer Part Number: ST72T774J9B1
• Manufacturer: STMicroelectronics

Specifications of ST72T774J9B1

• Cpu Family: ST7
• Device Core Size: 8b
• Frequency (max): 24MHz
• Interface Type: I2C/USB
• Program Memory Type: EPROM
• Program Memory Size: 60KB
• Total Internal Ram Size: 1KB
• # I/os (max): 31
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 1-chx8-bit
• On-chip Dac: 1-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 42
• Package Type: SPDIP
• Lead Free Status / Rohs Status: Specific Sites Compliant

CLOCK SYSTEM (Cont’d)
3.1.2 Crystal Resonator
The internal oscillator is designed to operate with
an
resonator in the frequency range specified for f
The circuit shown in
when
Recommended Crystal Values,” on page 19 lists
the recommended capacitance and feedback
resistance values. The crystal and associated
components should be mounted as close as
possible to the input pins in order to minimize
output distortion and start-up stabilization time.
Figure 8. Crystal/Ceramic Resonator
AT-cut
using
C
*Recommended for oscillator stability
L1
OSCIN
parallel resonant
a
CRYSTAL CLOCK
crystal,
Figure 8
1M*
OSCOUT
and
is recommended
quartz
C
Table 4,
L2
crystal
osc
“.
.
Table 4
Legend:
C
OSCIN and OSCOUT (the value includes the
external capacitance tied to the pin plus the
parasitic capacitance of the board and of the
device).
R
the quartz allowed.
Note: The tables are relative to the quartz crystal
only (not ceramic resonator).
3.1.3 External Clock
An external clock should be applied to the OSCIN
input with the OSCOUT pin not connected as
shown in
do not apply when using an external clock input.
The equivalent specification of the external clock
source should be used.
Figure 9. External Clock Source Connections
24 Mhz
L1
SMAX
R
SMAX
C
C
, C
L1
L2
L2
= Maximum series parasitic resistance of
.
Recommended Crysta
Figure
= Maximum total capacitance on pins
70
22
22
ST72774/ST727754/ST72734
9. The Crystal clock specifications
EXTERNAL
CLOCK
OSCIN
25
47
47
OSCOUT
NC
l
20
56
56
Values
Ohms
Unit
19/144
pf
pf